Regulators are breathing devices that allow scuba divers to breathe air, or the like, while under water. The regulator uses valves to release air from high pressure tanks, typically through the action of an inhalation responsive diaphragm. Most often, a first stage regulator is attached to the tank. A second stage regulator is then connected to the first by a flexible hose and is supported by a mouthpiece retained in the mouth of the diver. This configuration requires minimal breathing effort since it locates the inhalation responsive elements closer to the center of pressure of the diver's lungs.
Regulators are frequently shared by many divers, especially in rental operations and diver training programs. Pathogenic entities from one diver can be transmitted to the next. Some bacteria, such as tuberculosis, have become resistant to antibiotics. Hepatitis is difficult to kill and can survive on dry surfaces for great periods of time. And lethal new viruses, such as HIV, Marburg, and Ebola are emerging with an alarming frequency. Regulators are rinsed with fresh water after use, but this has little pathogen inactivating value. There is growing concern over this problem and some instructional agencies have even discontinued the so-called buddy breathing exercise of passing the same regulator back and forth between two divers.
U.S. Pat. No. 5,755,222, to Pansard and U.S. Pat. No. 5,829,432 to Semeia disclose fasteners to facilitate mouthpiece replacement and many rental operations now require divers to use their own personal mouthpieces. However, it is not enough to simply replace the mouthpiece to prevent the transmission of pathogenic entities between divers who share a common regulator. Pathogenic entities can also be carried past the mouthpiece and into the regulator with exhaled air and saliva, and once there, can be transmitted to the next user. In our previous patent application, we disclosed a mouthpiece having integral unidirectional fluid pathways to prevent pathogens in the divers exhalation and saliva from contaminating the regulator itself.
It is becoming increasingly common for divers to replace the mouthpiece of diving regulators before use. But even with quick release fasteners, it is not always easy to replace the mouthpiece. Not all regulator ports are the same size and it is sometimes difficult to fit a small mouthpiece over a large port and anchor it in place with a fastener, particularly if the divers hands are cold and wet.
One problem encountered when a mouthpiece having an integral exhaust port is used with a second stage diving regulator is that bubbles can pass in front of the diver's face and obscure his line of vision during exhalation. Although not a safety issue, bubbles can be irritating to the diver.
Second stage regulators have an exhaust port built into the regulator housing. When used with a mouthpiece having its own integral exhaust pathway, the exhaust port in the regulator housing can be used to help clear the regulator of water should it become flooded but may allow water to leak into the regulator. One diver may wish to make use of the exhaust port in the regulator while another diver might not. And so the problem arises as to what to do with the exhaust port in the regulator when the regulator is being used with a mouthpiece having its own integral exhaust pathway.